1. Field of the Invention
The present invention relates to a fishing reel, particularly to a fishing reel for winding and releasing a fishing line.
2. Background Art
Some fishing reels are configured to wind and release a fishing line while being attached to a fishing rod. Such fishing reels are mainly classified into the spinning reels and the dual-bearing reels. A fishing reel of the both types generally includes a reel unit, a spool shaft, and a spool. The reel unit is attached to the fishing rod. The spool shaft is supported by the reel unit. The spool is attached to the spool shaft for winding the fishing line. More specifically, a dual-bearing reel has a structure in which the spool is rotatably supported by the reel unit, whereas a spinning reel has a structure in which the spool is attached to the reel unit while being movably back and forth. For example, the above structures are described in Japan Registered Utility Model Publication No. JP-U-H05-002679 and Japan Laid-open Patent Application Publication Nos. JP-A-H11-206287 and JP-A-2007-097474.
In the aforementioned fishing reels, the spool is integrally made of either synthetic resin or light metal (e.g., aluminum alloy, magnesium alloy, etc.). The spool shaft is made of, for instance, stainless alloy. The spool shaft is supported by at least a bearing attached to the reel unit. Alternatively, the spool shaft supports a pinion gear and the spool.
Further, it has been widely known that some components for the fishing reels intended to be often used outside. Especially, the components are made of magnesium alloy having a coating made of coating material on the surface thereof. With such coating, the magnesium-alloy components are prevented from being exposed to corrosion atmosphere. Thus, corrosion resistance of the components can be enhanced. However, the magnesium-alloy components can have the following drawbacks when other components made of metal (e.g., stainless alloy) are disposed closer to the magnesium-alloy components. For example, galvanic corrosion can be caused in the magnesium-alloy components when conductive liquid (e.g., salty water) intrudes into an area between the other metal components and the magnesium-alloy components. This is due to localized electric cells to be formed by means of difference in ionization tendency between magnesium alloy and the other metal.
Some structures have been proposed so far for solving the aforementioned drawbacks. In the structures, an aluminum-alloy component is interposed between a stainless-alloy component and a magnesium-alloy component in consideration of the fact that aluminum has similar ionization tendency to magnesium. For example, Japan Laid-open Patent Application Publication No. JP-A-H11-225633 describes one of the well-known structures. In this structure, localized electric cells are prevented from being easily formed between the magnesium-alloy spool and the stainless-alloy spool shaft due to the aluminum-alloy sleeve interposed between the magnesium-alloy spool and the stainless-alloy spool shaft. Therefore, galvanic corrosion can be prevented in the magnesium-alloy spool.
In the aforementioned well-known fishing reels, the outer peripheral surface of the spool shaft and the inner peripheral surface of a bearing or a pinion gear are rotated relatively to each other with a high load or at a high speed. Such relative rotation with a high load or at a high speed can result in burnout between the outer peripheral surface of the spool shaft and the inner peripheral surface of the bearing or the pinion gear. To prevent the burnout, oil or grease is filled between the outer peripheral surface of the spool shaft and the inner peripheral surface of the bearing or the pinion gear. However, oil or grease can flow out due to intrusion of sea water or due to washing by water after use. Therefore, anglers are required to frequently supply oil or grease between the outer peripheral surface of the spool shaft and the inner peripheral surface of the bearing or the pinion gear.
Further, the well-known fishing reel has the structure in which the aluminum-alloy sleeve is interposed between the stainless-alloy spool shaft and the magnesium-alloy spool. Thus, the additional sleeve made of aluminum alloy is required. This increases the number of components. In addition, manufacturing cost can be thereby increased.
Yet further, the well-known fishing reel has the structure in which the spool is supported by the spool shaft through the sleeve. Therefore, a relative positional error is easily produced between the spool and the spool shaft. This can result in run-out of the outer periphery of the spool with respect to the spool shaft.
It is an advantage of the present invention to enhance abrasion resistance of the spool shaft and reduce frictional resistance between the outer peripheral surface of the spool shaft and the inner peripheral surface of the bearing or the pinion gear.
It is another advantage of the present invention to reduce a relative positional error between a spool and a spool shaft in fishing components as much as possible, reduce manufacturing cost, and prevent galvanic corrosion of a component made of magnesium alloy.